The present invention pertains to disposable absorbent training pants for children, and more particularly to improved waist elastic systems therefor.
Current disposable absorbent training pants for children going through the potty training stage have proved to be a particularly desirable and useful product. This is especially true for the child, when he or she has outgrown, or believe they have outgrown, diapers. Diapers are for babies, and most children do not like being identified with or as babies. Consequently, these children do not want to wear baby diapers, and instead prefer to wear a training pant that looks like adult underwear.
One problem with current training pants, however, is that they do not provide optimum comfort and ease of use, i.e., ease of pulling up or pulling down, over a wide weight or size range and for an extended period of time. This discomfort, and difficulty in pulling up or pulling down, very often frustrates the child to the point that potty training is delayed due to the child's displeasure with and difficulty in using the product.
One reason current training pants do not provide optimum comfort and ease of use is the fact that one training pant size is intended for use by children within a particular range of weights or sizes. This requires a single size training pant to fit children with different size waists. In practice, this means that the training pant will not provide a substantially uniform low tension over the required waist size range. For example, one specific training pant size may be designed to fit children within a weight range of 25-35 pounds. This weight range includes a wide range of waist sizes. Generally, the training pant will fit one particular weight, i.e., intermediate waist size, well enough to provide some degree of satisfaction. However, at the low weight end, i.e., the smallest waist size, an elastic waistband must be used to gather the excess material at the waist opening. However, the tension provided by the retracted elastic waistband can be too high, thereby causing discomfort and/or difficulty in pulling the pant up or down for the smaller to intermediate size children.
At the high end of the weight range, where the waist size is largest, the elastic waistband will extend its maximum allowable length to accommodate the larger waist. However, when fully extended, it can exert too high of a tension against the child's waist. Again, this results in discomfort, possible redmarking, and difficulty in pulling the pant up and down, thereby delaying potty training.
Thus, the fact that a single size training pant is designed to fit wide weight ranges has prevented them from providing substantially uniform low tensions over the corresponding wide size ranges over an extended period of time. Yet, this is an extremely desirable feature which, if available, would provide a training pant comfortable to the child, and easy to pull up or down. Thus, as a child would grow into, and then out of, a specified weight range for a specific training pant size, then the child would have a substantially uniform force or tension at the waist during that period of wearing the specific size training pant; but, this feature is not available in current children's disposable absorbent training pants.
Various designs of elastic waistbands have been used in these training pants, such as a single wide elastic member or a plurality of narrow elastic members. The waistbands may fully, or only partially, surround the waist opening. Generally, these elastic waistbands are incorporated by one of two methods. The first method incorporates the elastic waistbands when they are in an extended, tensioned state. The second method incorporates the elastic waistbands while they are in a relaxed, untensioned state. The latter method may require the use of a special elastic material, such as a heat-elasticizable material.
In both of these methods, the elastic waistbands generally are joined to multiple layers of material. For example, the elastic waistbands can be adhesively joined between two adjacent layers of material, such as, for example, the topsheet and backsheet of the training pant. In some cases, the elastic waistbands are first adhesively joined to a carrier sheet of material, and then the carrier sheet and elastic waistbands are adhesively joined between the adjacent layers.
The application of adhesive in these methods is generally accomplished by partially or totally coating the mutually facing surfaces of the adjacent layers, or by applying the adhesive in a bead to at least one of the layers. The latter method usually involves a continuous bead pattern, such as a wave-like pattern of adhesive.
Other methods or patterns for applying adhesive are available, and include joining the elastic waistbands along their full or entire length to multiple layers of material.